Ok, I'm looking at getting sleeves and boring.. all that jazz.

I could either get a 81.5mm piston or a 84mm piston.

If I have a 1.8, what will getting an 84mm bore do to that figure?

What are your thoughts between 81.5mm and 84mm?

Thanks!

 

Displacement is

Pi*r^2 * stroke * # cylinders

so if you're starting out on a 1.8, an 84mm piston will put you just under 2.0L, but close enough to call it 2.0L

 

In just doing some quick calculations (assuming you're staring with 1797cc), a piston 81.25mm will bring you up to 1808cc and a 84mm piston will get you up to 1933cc.

Essentially you'll have a 1.9L with 84mm pistons. You'll also get some added tq from the increased displacement. Any idea what compression you'll be shooting for? Extra compression will also give you some more power across the board.

I'm sure there's other people on the board that can give you more detailed info than this, but at least it's a starting point. Keep in mind that the 81.25 pistons can go in with minimal work, while the 84mm will probably require a resleeve.

EDIT: I forgot you're boosted. My reply is presented from an N/A perspective ... I always forget about you crazy F/I guys.

 

Is the engine a B18C or B18a/b?

A 2.0L boosted LS can be quite robust and fast

 

Hahaha it's never enough, is it?!

If you're going to sleeve the motor you might as well punch it out to 84 mm bore while you're in there.

 

Going with AEBS for sure. Putting in custom AEBS/Someone else 9.5:1 pistons and I have the option of either 81.5 or 84, that's why I'm asking.

Going to get it o-ringed too. :naughty:

No, IT'S NEVER ENOUGH!!! *Dr. Evil laugh* :chuckles:

:edit: B18C1

:edit2: would you recommend an 84mm on a daily driver? I currently have a GSR radiator and FAL fan - FYI.

 

84 mm is the FI standard for resleeved motors. Shouldn't be an issue. I know some people go farther than that on NA motors.

81.5 would be for keeping stock bore... probably just for classing reasons.

 

h:

84 it is then.